Stirling Cycle Device

ABSTRACT

A Stirling cycle device includes a housing with an inner wall, and a regenerator attached to the inner wall of the housing, wherein the regenerator, made of wool or chemical fiber, is composed of two, three, or four sub-regenerators and the height of the regenerator is independent on number of sub-regenerators. As the regenerator is made of wool or chemical fiber, which may ensure a sufficient permeability and heat storage performance; as the regenerator is composed of a plurality of sub-regenerators, clearances may be formed between each two sub-regenerators, and as the clearances have a density less than the surrounding sub-regenerators, these clearances may be used for energy storage, heat insulation and air circulation. Consequently, the refrigerating performance of the cycle device is improved as the efficiency of pre-cooling and pre-heating of the working gas in the regenerator is improved.

RELATED APPLICATIONS

This application claims the benefit of Chinese Invention Application201410034789.2, filed on Jan. 24, 2014 and Chinese Invention Application201410035215.7, filed on Jan. 24, 2014. The specifications of bothapplications are incorporated here by this reference.

FIELD OF THE INVENTION

The present invention relates to a Stirling cycle device for cooling orheating or the like.

DESCRIPTION OF THE PRIOR ART

A Stirling cycle device is a device in which a displacer and a pistonare coaxially provided inside an air cylinder so that when in operation,the reciprocating motion of the piston drives the gas to expand orcompress periodically in order to generate cold (or heat). A compressionchamber is formed between one end of the displacer and the piston whilean expansion chamber is formed at the other end of the displacer, aregenerator is disposed between the compression chamber and theexpansion chamber, and the two chambers are communicated to each otherthrough the regenerator to form a closed loop inside the cycle device.Heat absorbers (at the end where the expansion chamber is formed) andheat sinks (at the end where the compression chamber is formed) areprovided at two ends of the regenerator, each heat sink having coolingfins which facilitate heat exchange with the outside air. The piston isdriven to allow the gas inside the compressed chamber to be compressedand fed into the regenerator and further conveyed into the expansionchamber, with heat of the gas being accumulated by the regenerator,hereafter, the compressed high-pressure working gas expands inside theexpansion chamber. Then, the temperature falls, the piston resets, andthe working gas returns back to the compression chamber through theregenerator again. The heat accumulated inside the regenerator isimparted to the working gas so that the temperature of the working gasrises. By repeated cycles, the temperature of the heat absorbersgradually becomes low, to be extremely low. The principle of heating issimilar.

In the prior art, the regenerator is usually made of resin. Such aregenerator, however, is complicated in manufacturing, and therefrigerating efficiency is decreased due to the poor permeability,which hinders the circulation of cold air and hot air in some extent, ofthe resin. For this reason, regenerators made of other materials havebeen disclosed in the prior art. For example, a Stirling refrigeratordisclosed in a Chinese Patent Application, the application No.00817515.2, the regenerator is a matrix of fine wire or a ring-shapedgap formed by wounding foil. However, due to the large coefficient ofheat conductivity, quick heat radiation and poor energy storageperformance of the wire, both the pre-cooling of hot air when it passesthrough the regenerator and the pre-heating of cold air when it passesthrough the regenerator are insufficient. As a result, the refrigeratingefficiency is also decreased.

In addition, to improve the heat exchange efficiency of the coolingfins, the cooling fins require a large contact area and a large weight.However, the existing cooling fins, for example, those used in a heatexchanger for a Stirling refrigerator as disclosed in a Chinese PatentApplication (Application No. 01815042.X), are integrally formed anannular corrugated fin that is produced by forming a sheet material,corrugated so as to have a large number of grooves, into a cylindricalshape with the grooves parallel to an axis of the cylindrical shape.When it is intended to ensure smooth circulation of gas, the sides ofthe grooves of the corrugated fin have a small contact area (or even nocontact), i.e., large opening of the V-grooves, thereby resulting in lowheat conductivity; and when it is intended to improve the heatconductivity, the cooling fins should have a large contact area (i.e.,large cooling area), for this purpose, the grooves are squeezed, theV-shape of the grooves is compressed and the opening of the V-shape isreduced (or even closed), consequently, the circulation of gas ishindered. That is, the existing folding manner is unable to ensure boththe smooth circulation of gas and the improved heat conductivity, andthus unable to realize high heat exchange efficiency.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide a Stirling cycledevice with improved refrigerating efficiency.

For achieving the above stated object, a Stirling cycle devicecomprises: a housing with an inner wall; a regenerator attached to theinner wall of the housing, the regenerator having a thickness, a top,and a bottom, wherein the regenerator, made of wool or chemical fiber,is composed of two, three, or four sub-regenerators and the height ofthe regenerator is independent on number of sub-regenerators.

The regenerator has a height between 34.5 mm and 36 mm, a wall thicknessbetween 4.8 mm and 5 mm, and an outer diameter between 36.6 mm and 36.8mm. The permeability and the heat insulation may be best balanced bycontrolling the overall weight of the regenerator, and the refrigeratingefficiency is thus improved.

As a preference, a first cooling element is disposed on the top and asecond cooling element is disposed on the bottom of the regenerator, twocooling elements are attached to the housing, each cooling element isformed with a heat dissipation element folded in a continuous wavefashion, and the heat dissipation element has a start and an end, thestart and the end of the heat dissipation element attached to each otherforming a cylinder, the cylinder has a transverse section with an innerside and an outer side, multiple arch units are formed on the inner sideand the outer side of the transverse section, each two adjacent archunits are attached closely;

multiple pores are formed in the heat dissipation element, the pores aredistributed in an upper row and a lower row, and the pores in the upperrow and the pores in the lower row are interlaced.

Such a folding manner of compact compression of the cooling elements 3that each cooling element has large contact area and large weight;furthermore, the heat dissipation element is compressed leftward andrightward, upward and downward to form more pores and contact area,thereby the optimum gas permeability and heat conductivity can beachieved.

As a preference, each of the first cooling element and the secondcooling element is attached to the housing through a positioned ring.

As a preference, each heat dissipation element is made of copper oraluminum with high heat conductivity.

As a preference, the transverse section of the cylinder of each heatdissipation element has a perimeter between 98 mm and 98.5 mm, theannular thickness of the transverse section is between 4.6 mm and 4.7mm, and the height of the cylinder is between 6.8 mm and 7 mm.

As a preference, each of the first cooling element and the secondcooling element has multiple pores with a porosity between 10% and 90%.

Compared with the prior art, in the present invention,

first, as the regenerator 2 is made of wool or chemical fiber, which mayensure a sufficient permeability and heat storage performance;

second, as the regenerator is composed of a plurality ofsub-regenerators, clearances may be formed between each twosub-regenerators, and as the clearances have a density less than thesurrounding sub-regenerators, these clearances may be used for energystorage, heat insulation and air circulation. Consequently, therefrigerating performance of the cycle device is improved as theefficiency of pre-cooling and pre-heating of the working gas in theregenerator is improved;

third, each cooling element is formed with a heat dissipation elementfolded in a continuous wave fashion, so that more pores and contact areaare formed, and the optimum gas permeability and heat conductivity canbe achieved, thereby improve heat conductivity.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a sectional view of a Stirling cycle device in accordance withan embodiment of the present invention;

FIG. 2 is a sectional view of a regenerator in accordance with theembodiment of the present invention;

FIG. 3 is a view of a heat dissipation element after folded in acontinuous wave fashion but not yet form a cylinder in accordance withthe embodiment of the present invention;

FIG. 4 is perspective view of a cooling element (a cylinder) inaccordance with the embodiment of the present invention;

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

To enable a further understanding of the innovative and technologicalcontent of the invention herein, refer to the detailed description ofthe invention and the accompanying drawings below:

Referring to FIG. 1 and FIG. 2, a Stirling cycle device comprises ahousing 1 with an inner wall, a regenerator 2 with a thickness, a top,and a bottom, and a first cooling element 3 is disposed on the top and asecond cooling element 3 is disposed on the bottom of the regenerator 2,a displacer 4 is disposed in the regenerator 2; the remainingconfiguration of the cycle device may be employed from the prior art andwill not be repeated here.

The regenerator 2, the two cooling elements 3 and displacer 4 aredisposed inside the housing 1, the regenerator 2 are cylindrical, theregenerator 2 and the two cooling elements 3 are attached to the innerwall of the housing 1, each of two cooling elements 3 is a cylinder andis attached to the housing 1 through a positioned ring 31.

In the present invention, the regenerator 2 is made of wool or chemicalfiber, which is low in cost and simple in manufacturing process;furthermore, as wool or chemical fiber may ensure a sufficientpermeability, the circulation of gas is smooth. Additionally, as thecoefficient of heat conductivity of wool or chemical fiber is far belowthat of wire, good heat storage performance is achieved while ensuringgood permeability. Hence, the refrigerating efficiency of the Stirlingcycle can be improved effectively.

In order to further improve the refrigerating efficiency, theregenerator 2 is composed of two, three, or four sub-regenerators andthe height of the regenerator 2 is independent on number ofsub-regenerators. That is, when the regenerator 2 is composed of twosub-regenerators, the height of the regenerator 2 is between 34.5 mm and36 mm, each sub-regenerator has a height between 17.25 mm and 18 mm, anda wall thickness between 4.8 mm and 5 mm, and an outer diameter between36.6 mm and 36.8 mm. At this time, the sizes of the wall thickness andthe outer diameter of each sub-regenerator are the same. The regenerator2 is composed of three or four sub-regenerators are similar.

Therefore, the weight of the regenerator 2 may be controlled to bestbalance the permeability and the heat insulation, and the refrigeratingefficiency is thus improved. Furthermore, as the regenerator is composedof a plurality of sub-regenerators, clearances may be formed betweeneach two sub-regenerators, and as the clearances have a density lessthan the surrounding sub-regenerators, these clearances may be used forenergy storage, heat insulation and air circulation. Consequently, coldair, when it flows through the regenerator 2 into the compressionchamber, may be sufficiently pre-heated by heat stored inside theclearances; and hot air, when it flows through the regenerator 2 intoexpansion chamber, may be sufficiently pre-cooled by cold stored insidethe clearances. The refrigerating performance of the cycle device isimproved as the efficiency of pre-cooling and pre-heating of the workinggas in the regenerator 2 is improved.

Referring to FIG. 3 and FIG. 4, views of the cooling element 3 areshown. Each cooling element 3 is formed with a heat dissipation elementfolded in a continuous wave fashion, and the heat dissipation elementhas a start and an end, the start and the end of the heat dissipationelement attached to each other forming a cylinder(the width of the heatdissipation element serves as the height of the cylinder), the cylinderhas a transverse section with an inner side(which is close to thecentral hole of the cylinder) and an outer side(which is away from thecentral hole of the cylinder), multiple arch units 32 are formed on theinner side and the outer side of the transverse section, each twoadjacent arch units 32 are attached closely, so that the surface of theinner side and the outer side of the cylinder are in wave.

Multiple pores 33 are formed in the heat dissipation element 3, thepores 33 are distributed in an upper row and a lower row, and the pores33 in the upper row and the pores in the lower row are interlaced. Eachof the first cooling element 3 and the second cooling element 3 hasmultiple pores 33 with a porosity between 10% and 90%.

Each heat dissipation element is made of copper or aluminum with highheat conductivity. As shown in FIG. 4, the transverse section of thecylinder of each heat dissipation element has a perimeter L(approximately equal to the length of the heat dissipation element afterfolded in a continuous wave fashion but not yet form a cylinder) between98 mm and 98.5 mm, the annular thickness T of the transverse section isbetween 4.6 mm and 4.7 mm, and the height H of the cylinder is between6.8 mm and 7 mm.

Such a folding manner of compact compression of the cooling elements 3that each cooling element has large contact area and large weight;furthermore, the heat dissipation element is compressed leftward andrightward, upward and downward to form more pores and contact area,thereby the optimum gas permeability and heat conductivity can beachieved. That is, during the folding and compression, the coolingelements have enough pores to realize smooth circulation of gas, andalso have enough contact area(each two adjacent arch units 32 with thepores interlaced distributed in an upper row or a lower row alwaysattach closely, so that the cooling elements always maintain pores andcontact surfaces during the folding and compression) to improve heatconductivity.

1. A Stirling cycle device, comprising: a housing with an inner wall; aregenerator attached to the inner wall of the housing, the regeneratorhaving a thickness, a top, and a bottom, wherein the regenerator, madeof wool or chemical fiber, is composed of two, three, or foursub-regenerators and the height of the regenerator is independent onnumber of sub-regenerators.
 2. The Stirling cycle device of claim 1,wherein the regenerator has a height between 34.5 mm and 36 mm, a wallthickness between 4.8 mm and 5 mm, and an outer diameter between 36.6 mmand 36.8 mm.
 3. The Stirling cycle device of claim 1, wherein a firstcooling element is disposed on the top and a second cooling element isdisposed on the bottom of the regenerator, two cooling elements areattached to the housing, each cooling element is formed with a heatdissipation element folded in a continuous wave fashion, and the heatdissipation element has a start and an end, the start and the end of theheat dissipation element attached to each other forming a cylinder, thecylinder has a transverse section with an inner side and an outer side,multiple arch units are formed on the inner side and the outer side ofthe transverse section, each two adjacent arch units are attachedclosely; multiple pores are formed in the heat dissipation element, thepores are distributed in an upper row and a lower row, and the pores inthe upper row and the pores in the lower row are interlaced.
 4. TheStirling cycle device of claim 3, wherein each of the first coolingelement and the second cooling element is attached to the housingthrough a positioned ring.
 5. The Stirling cycle device of claim 3,wherein each heat dissipation element is made of copper or aluminum withhigh heat conductivity.
 6. The Stirling cycle device of claim 3, whereinthe transverse section of the cylinder of each heat dissipation elementhas a perimeter between 98 mm and 98.5 mm, the annular thickness of thetransverse section is between 4.6 mm and 4.7 mm, and the height of thecylinder is between 6.8 mm and 7 mm.
 7. The Stirling cycle device ofclaim 3, wherein each of the first cooling element and the secondcooling element has multiple pores with a porosity between 10% and 90%.